Process for forming a patterned thin film structure on a substrate

ABSTRACT

A process for forming a patterned thin film structure on a substrate is disclosed. A pattern is printed with a material, such as a masking coating or an ink, on the substrate, the pattern being such that, in one embodiment, the desired thin film structures will be formed in the areas where the printed material is not present, i.e., a negative image of thin film structure to be formed is printed. In another embodiment, the pattern is printed with a material that is difficult to strip from the substrate, and the desired thin film structures will be formed in the areas where the printed material is present, i.e., a positive image of the thin film structure is printed. The thin film material is deposited on the patterned substrate, and the undesired area is stripped, leaving behind the patterned thin film structures.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of co-pending U.S.application Ser. No. 10/422,557, filed Apr.23, 2003, the content ofwhich is incorporated herein by reference in its entirety. Saidapplication Ser. No. 10/422,557 claims the benefit of U.S. ProvisionalApplication Serial No. 60/375,902, filed Apr. 24, 2002, the content ofwhich is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates generally to displays. A processfor forming a patterned thin film layer on a substrate is disclosed.

BACKGROUND OF THE INVENTION

[0003] A plastic display, such as an electrophoretic display, typicallycomprises two electrodes, at least one of which is patterned, and adisplay medium layer. Biasing voltages typically are applied selectivelyto the electrodes to control the state of the portion(s) of the displaymedium associated with the electrodes being biased. For example, atypical passive matrix electrophoretic display may comprise an array ofelectrophoretic cells arranged in rows and columns and sandwichedbetween a top and bottom electrode layer. The top electrode layer maycomprise, for example, a series of transparent column electrodespositioned over the columns of electrophoretic cells and the bottomelectrode layer may comprise a series of row electrodes positionedbeneath the rows of electrophoretic cells. Several types of passivematrix electrophoretic displays are described in U.S. Provisional PatentApplication Serial No. 60/322,635 entitled “An Improved ElectrophoreticDisplay with Gating Electrodes,” filed Sep. 12, 2001, U.S. ProvisionalPatent Application Serial No. 60/313,146 entitled “An ImprovedElectrophoretic Display with Dual mode Switching,” filed on Jul. 17,2001, and U.S. Provisional Patent Application Serial No. 60/306,312entitled “An Improved Electrophoretic Display with In-Plane Switching,”filed on Aug. 17, 2001, all of which are hereby incorporated byreference for all purposes.

[0004] One typical prior art approach to fabricating the patternedelectrode layer(s) for such a plastic display typically involves the useof photolithographic techniques and chemical etching. Conductor filmsuseful for plastic display applications may be formed by a process suchas laminating, electroplating, sputtering, vacuum deposition, orcombinations of more than one process for forming a conductor film ontoa plastic substrate. Useful thin film conductors include metalconductors such as, for example, aluminum, copper, zinc, tin,molybdenum, nickel, chromium, silver, gold, iron, indium, thallium,titanium, tantalum, tungsten, rhodium, palladium, platinum and/orcobalt, etc., and metal oxide conductors such as indium tin oxide (ITO)and indium zinc oxide (IZO), as well as alloys or multilayer compositefilms derived from the aforementioned metals and/or metal oxides, e.g.,aluminum zinc oxide, gadolinium indium oxide, tin oxide, orfluorine-doped indium oxide. Further, the thin film structures describedherein may comprise either a single layer thin film or a multilayer thinfilm. ITO films are of particularly interest in many applicationsbecause of their high degree of transmission in the visible lightregion. Useful plastic substrates include epoxy resins, polyimide,polysulfone, polyarylether, polycarbonate (PC), polyethyleneterephthalate (PET), polyethylene terenaphthalate (PEN), poly(cyclicolefin), and their composites. The conductor-on-plastics films aretypically patterned by a photolithographic process which comprisesseveral time consuming and high cost steps including (1) coating theconductor film with photoresist; (2) patterning the photoresist byimage-wise exposing it through a photomask to, for example, ultravioletlight; (3) “developing” the patterned image by removing the photoresistfrom either the exposed or the unexposed areas, depending on the type ofphotoresist used, to uncover the conductor film in areas from which itis to be removed (i.e., areas where no electrode or other conductivestructures is to be located); (4) using a chemical etching process toremove the conductor film from the areas from which the photoresist hasbeen removed; and (5) stripping the remaining photoresist to uncover theelectrodes and/or other patterned conductive structures.

[0005] For mass fabrication of a plastic display, such as anelectrophoretic display, it may be advantageous to employ a continuousroll-to-roll process. However, the photolithographic approach describedabove is not well suited to such a roll-to-roll process, as certain ofthe processing steps, such as the image-wise exposure, are timeconsuming and require careful registration and alignment of the mask andthe moving target area. In addition, development and stripping ofphotoresist and treatment of waste from the chemical etching process maybe time consuming and expensive, in addition to potentially posing anenvironmental hazard.

[0006] Therefore, there is a need for a process for forming patternedconductive structures on a plastic substrate, for use in a plasticdisplay such as an electrophoretic display, that does not require theuse of photolithography or chemical etching and that is suitable for usein a continuous roll-to-roll process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings,wherein like reference numerals designate like structural elements, andin which:

[0008]FIG. 1 is a flowchart illustrating a process used in oneembodiment to form a patterned thin film conductor on a substrate.

[0009]FIGS. 2A through 2D illustrate a schematic plan view of a seriesof processing steps used to form four column electrodes on a substrate.

[0010]FIGS. 3A through 3D further illustrate the example shown in FIGS.2A through 2D by providing a schematic front cross-sectional view of theprocessing steps shown in FIGS. 2A through 2D.

[0011]FIGS. 4A and 4B illustrate a schematic plan view of an example inwhich segment electrodes for a seven segment display are formed using anembodiment of the process described herein.

[0012] FIGS. 5A-1 through 5D-2 illustrate an alternative process used inone embodiment to form a patterned thin film conductor on a substrate.

[0013] FIGS. 6A-1 through 6F-2 illustrate a further alternative to theprocess shown in FIGS. 1-4.

DETAILED DESCRIPTION

[0014] A detailed description of a preferred embodiment of the inventionis provided below. While the invention is described in conjunction withthat preferred embodiment, it should be understood that the invention isnot limited to any one embodiment. On the contrary, the scope of theinvention is limited only by the appended claims and the inventionencompasses numerous alternatives, modifications and equivalents. Forthe purpose of example, numerous specific details are set forth in thefollowing description in order to provide a thorough understanding ofthe present invention. The present invention may be practiced accordingto the claims without some or all of these specific details. For thepurpose of clarity, technical material that is known in the technicalfields related to the invention has not been described in detail so thatthe present invention is not unnecessarily obscured.

[0015] A process for forming a patterned thin film structure on asubstrate is disclosed. A pattern is printed with a material, such as amasking coating or an ink, on the substrate, the pattern being suchthat, in one embodiment, the desired thin film structures will be formedin the areas where the printed material is not present, i.e., a negativeimage of the thin film structure to be formed is printed. In anotherembodiment, the pattern is printed with a material that is difficult tostrip from the substrate, and the desired thin film structures will beformed in the areas where the printed material is present, i.e., apositive image of the thin film structure is printed. The thin filmmaterial is deposited on the patterned substrate, and the undesired areais stripped, leaving behind the patterned electrode structures.

[0016]FIG. 1 is a flowchart illustrating a process used in oneembodiment to form a patterned thin film conductor on a substrate. Theprocess begins in step 102 and proceeds to step 104 in which a negativeimage of the thin film structures to be formed is printed on the surfaceof the substrate using a masking coating or ink. In one embodiment, themasking coating or ink may be stripped using an aqueous solution and/oranother common solvent. In step 104, a negative image of the thin filmstructures to be formed is printed in the sense that the masking coatingor ink will cover areas of the substrate where the thin film materialwill not be present upon completion of the process and will not coverareas of the substrate where the thin film material will be present. Inessence, the ink pattern serves as a mask for the subsequent depositionof thin film material, as described more fully below in connection withstep 106.

[0017] Any suitable printing techniques, such as flexographic,driographic, electrophotographic, and lithographic printing, may be usedto print the ink pattern on the substrate. In certain applications,other printing techniques, such as stamping, screen printing, gravureprinting, ink jet, and thermal printing may be suitable, depending onthe resolution required. In addition, the masking coating or ink doesnot need to be optically contrasted with the substrate, and can becolorless.

[0018] In one embodiment, the masking coating or ink comprises are-dispersible particulate. In one embodiment, the masking coating orink comprises 5-80% by weight, preferably 10-60% by weight based ondried weight of the masking ink/coating, of a re-dispersibleparticulate. In one embodiment, the masking coating or ink comprises awater-soluble or water-dispersible polymer as a binder. Typical examplesof water soluble polymers include, but are not limited to, polyvinylalcohol, polyvinylpyrrolidone, polyvinylpyridine, polyacrylic acid,polymethacrylic acid, polyacrylamide, polyethyleneglycol,poly(ethylene-co-maleic anhydride), poly (vinylether-co-maleicanhydride), poly(styrene-co-maleic anhydride),poly(butyelene-co-itaconic acid), PEOX, polystyrene sulfonate, cellulosederivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose,methyl cellulose, carboxymethyl cellulose, xanthan gum, gum Arabic,gelatin, lecitin, and their copolymers. In one such embodiment, thewater-dispersible polymer comprises a water- or alkaline-dispersiblewax, polyolefin, or acrylic latexes or dispersions. In one embodiment,the masking coating or ink comprises a solvent-soluble orsolvent-dispersible polymer as a binder. In one embodiment, the maskingcoating or ink comprises a re-dispersible particulate derived fromsilica, CaCO₃, CaSO₄, BaSO₄, Al₂O₃, TiO₂, hollow-spheres,non-film-forming latexes or dispersions, inorganic pigment(s), ororganic pigment(s). In one embodiment, the masking coating or inkcomprises a re-dispersible particulate comprising a polymeric orpolymeric composite particle. In one embodiment, including are-dispersible particulate in the masking coating or ink facilitatessubsequent stripping of the masking coating or ink. In one embodiment,including a re-dispersible particulate in the masking coating or inkfacilitates subsequent stripping of the masking coating or ink byreducing the thickness or integrity of the masking coating or ink layerand/or improving the permeation of a stripping solvent into the maskingcoating or ink layer during stripping.

[0019] In step 106, a thin film of material is deposited on thepatterned surface of the substrate. In one embodiment, the thin filmmaterial may be conductive, non-conductive, or semi-conductive. In oneembodiment, vapor deposition is used to deposit a thin film ofconductive material on the patterned side of the substrate in step 106.In such an embodiment, aluminum, copper, or any conductive materialsuitable for being deposited as a thin film through vapor deposition orspraying may be used as the conductive material. In one alternativeembodiment, the conductive material is deposited by sputter coating thepatterned side of the substrate with the conductive material. In such anembodiment, indium tin oxide (ITO) or any other conductive material suchas gold, silver, copper, iron, nickel, zinc, indium, chromium,aluminum-doped zinc oxide, gadolinium indium oxide, tin oxide, orfluorine-doped indium oxide, or any other conductive material suitablefor being deposited in a thin film through sputter coating may be used.

[0020] In step 108 of the process shown in FIG. 1, the masking coatingor ink is stripped from the patterned surface of the substrate on whichthe thin film material has been deposited in step 106. The stripping ofthe coating/ink in step 108 has the effect of stripping away the printedpattern formed in step 104 as well as the portion of the thin filmmaterial deposited in step 106 that was deposited on to the areas of thesubstrate where the coating/ink was present. As a result, the strippingsolvent is able to strip away the coating/ink pattern and the thin filmmaterial formed on the top surface of the coating/ink pattern, eventhough the stripping step is performed after the deposition of the thinfilm in step 106. The process shown in FIG. 1 then ends in step 110.Without limiting the generality of the present disclosure, it isbelieved that in certain embodiments at least part of the maskingcoating/ink printed in step 104 is exposed, or nearly so, to thestripping solvent, despite the masking patterns having been covered withthin film material as a result of the deposition process of step 106. Inone embodiment, low molecular weight additives such as plasticizers,surfactants, and residual monomers or solvents in the maskingcoating/ink may cause defects or micro-porosity in the thin film coatedon the ink, accelerating exposure of the masking coating to the solvent.The present disclosure contemplates that any suitable combination ofcoating/ink, thin film, and stripping process may be used, withoutlimiting the applicability of the present disclosure in any way, andwithout limiting the present disclosure to any particular strippingmechanism or theory. With respect to the process shown in FIG. 1, in anembodiment in which a conductive thin film structure, such as anelectrode or conductive trace, is being formed, the only requirement isthat the combination used be such that, upon stripping, the areas ofthin film formed on the substrate remain present and the areas of thinfilm formed on the strippable masking coating/ink be stripped away, orlargely so, such that the areas where the coating/ink pattern waspresent are not conductive, or sufficiently nearly so for the display tooperate properly.

[0021] The process described above does not require the use ofphotolithography and selective etching of the thin film layer to definepatterned thin film structures on a substrate. Instead, the ink patternis used to define, prior to the deposition of the thin film material,the shape of the thin film structures to be formed. Because a simplesolvent, such as water, aqueous solutions, alcohols, ketones, esters,amides, hydrocarbons, alkylbenzenes, pyrrolidones, sulfones, DMSO, ormany other common organic solvents or solvent mixture, may be used tostrip away the ink and the thin film material formed on top of the inkpattern, the patterned thin film structures may be formed via aroll-to-roll process that is not as time consuming, not as expensive,and does not generate as much toxic chemical waste as thephotolithographic and chemical etching techniques used in prior artphotolithographic processes.

[0022] As noted above, one type of display that the above-describedprocess may be used in connection with is a passive matrix display, suchas a passive matrix electrophoretic display. A passive matrix displaymay, for example, comprise a patterned electrode layer comprising aplurality of column or row electrodes. FIGS. 2A through 2D illustrate aschematic plan view of a series of processing steps used to form fourcolumn electrodes on a substrate. FIG. 2A shows a plastic substrate 202.In FIG. 2B an ink pattern comprising lines 204 has been printed on thesubstrate 202. In the example shown in FIG. 2B the lines 204 define onthe substrate 202 areas on which four column electrodes will be formed,as described more fully below, in the areas of substrate 202 that arenot covered by the lines 204.

[0023] In FIG. 2C, a thin film layer 206 has been formed on thepatterned surface of the substrate, covering both the portions of thesubstrate 202 that are not covered by the ink lines 204 (shown by dashedlines in FIG. 2C) and the portions that are covered by the ink lines204. In FIG. 2D, the ink pattern has been stripped away, along with theportions of the thin film 206 that were deposited on the ink lines 204,exposing column electrodes 208. The respective column electrodes 208 areseparated from each other by the areas of the substrate 202 exposed bythe stripping away of the ink lines 204.

[0024]FIGS. 3A through 3D further illustrate the example shown in FIGS.2A through 2D by providing a schematic front cross-sectional view of theprocessing steps shown in FIGS. 2A through 2D. FIG. 3A shows a frontcross-sectional view of the substrate 202. FIG. 3B shows the ink lines204 formed on the substrate 202. As shown in FIG. 3C, the thin filmlayer 206 forms on the portions of the substrate not covered by thelines 204 and on the top and side surfaces of the polymer ink lines 204.Finally, FIG. 3D shows the column electrodes 208 that remain formed onthe substrate 202 subsequent to the stripping of the lines 204, whichhas the effect of stripping away both the ink lines 204 and any thinfilm material 206 formed on top of the ink lines 204.

[0025] While FIGS. 2A-2D and 3A-3D illustrate an example in which fourcolumn electrodes are formed on a plastic substrate, the coating/ink maybe printed in any pattern to define on the substrate thin filmstructures of any desired shape or size. FIGS. 4A and 4B illustrate aschematic plan view of an example in which segment electrodes for aseven segment display are formed using an embodiment of the processdescribed herein. FIG. 4A shows display electrode layer 400 comprising apolymer ink pattern 402 defining on a plastic substrate seven segmentelectrode areas 404 a-404 g in which the ink pattern 402 is not presentsuch that the underlying substrate is exposed. FIG. 4B shows the samedisplay electrode layer 400 subsequent to the steps of deposition of thethin film and stripping of the ink pattern. As shown in FIG. 4B, thestripping away of the ink exposes a background area 406 of the substrateon which no thin film structure is present. In addition, segmentelectrodes 408 a-408 g have been formed and remain in the segmentelectrode areas 404A-404G defined as described above in connection withFIG. 4A.

[0026] As is apparent from the above discussion, thin film structures ofany shape or size may be formed simply by defining through use of theprinted pattern areas on the substrate on which thin film structures areto be formed. The structures may include electrode structures such asthose described above and/or conductive traces or any other thin filmstructure desired.

[0027] The processes described herein may be used in one embodiment toform a top or bottom electrode layer to be disposed adjacent to anelectrophoretic display media layer. In one embodiment, theelectrophoretic display media comprises a layer of sealed microcups,each comprising a quantity of electrophoretic dispersion. In oneembodiment, a protective overcoat such as an antiglare protectivecoating comprising particulate filler may be applied onto the sealedmicrocups or the top (viewing side) electrode layer to further improvethe optical or physicomechanical properties of the finished panel.

[0028] In one embodiment, conductive thin film structures are formed onboth the top and bottom surfaces of the substrate, using the processdescribed herein first to form thin film structures on one side of thesubstrate and then to form thin film structures on the opposite side ofthe substrate using the same series of steps described above for formingthin film structures on one side of the substrate. In one embodiment,conductive thin film structures on the top surface of the substrate maybe connected electrically to conductive surfaces formed on the bottomsurface of the substrate by forming via holes and completing anelectrical connection through the via hole from a conductive structureon the top surface of the substrate to a conductive structure on thebottom surface of the substrate, as described in U.S. patent applicationSer. No. 10/422,413, which is incorporated herein by reference.

[0029] In one embodiment of the process illustrated in FIGS. 1-4, thecoating/ink used to pattern the substrate comprises Sun ChemicalAquabond AP blue ink and/or Sunester red ink (Sun Chemical, Northlake,Ill.) and the substrate comprises 5 mil thick Melinex 453 polyester(DuPont Teijin, Hopewell, Va.). The ink may be applied through a stencilusing a hand proofer with a #360 anilox roller. The ink may be driedwith a heat gun. The thin film material is deposited by loading thepatterned substrate into a DC-magnetron sputtering system to deposit ITOfilm up to about 100 nm thickness. The patterned substrate may be plasmatreated prior to deposition of the thin film. The ink pattern and thinfilm formed thereon is stripped by spraying the patterned substrate onwhich the thin film has been formed with acetone (Histological grade,Fisher Scientific) for 1 to 2 minutes at room temperature. The aboveprocessing steps result in the thin film (i.e., ITO) formed in the inkpattern being removed along with the ink, leaving an area on thesubstrate where no ITO coating is present such that no measurableconductivity in present in such areas where the ITO has been removed.

[0030] In one embodiment of the processes illustrated in FIGS. 1-4, FilmIII Warm Red ink (Environmental Inks and Coatings, Los Angeles, Calif.)is applied using a hand proofer to define a pattern or mask on asubstrate comprising 5 mil thick Melinex ST505 polyester (DuPont Teijin,Hopewell, Va.). The thin film is deposited by loading the patternedsubstrate into a DC-magnetron sputtering system to deposit ITO film upto about 100 nm thickness. The ink is washed from the ITO coatedpatterned substrate by spraying with acetone (Histological grade, FisherScientific) for 30 to 60 sec. The ITO formed on the ink is removed alongwith the ink, leaving an area where there is no ITO coating where theink pattern was printed.

[0031] In one embodiment of the processes illustrated in FIGS. 1-4, theink pattern is printed on 5 mil thick, 4507 Polyester (Transilwrap,Franklin Park, Ill.) using GP-217 Process Magenta ink (Ink Systems Inc.,Commerce, Calif.) on an offset press. The inked polyester is loaded in avacuum system for aluminum evaporation at the film thickness of 120 nm.The aluminum coated polyester is immersed in hot (T=about 80° C.) methylethyl ketone (Certified grade, Fisher Scientific, MEK) for 15 seconds,and then wiped gently with a cotton swab soaked in MEK. This processstrips the inked area from the polyester, along with the aluminum on topof the ink. The stripping results in a negative image from the ink,i.e., there is no aluminum coating in the areas where the ink patternwas printed, with the remaining areas (i.e., where the ink pattern wasnot present) being coated with aluminum.

[0032] In one embodiment of the processes illustrated in FIGS. 1-4, anink pattern is made on a roll of 5 mil thick, 12″ wide Melinex 453polyester (Plastics Suppliers, Fullerton Calif.) using Film III Warm Redink (Environmental Inks and Coatings, Los Angeles, Calif.) on a MarkAndy 4200 flexographic press. The patterned polyester is loaded into aDC-magnetron sputtering system to deposit ITO film for about 100 nm.Prior to the deposition, the ink coated sheets may be plasma treated.The ITO coated polyester is then immersed in a jar of hot (T=about 80°C.) MEK and cleaned ultrasonically using a Fisher Scientific FS220Hultrasonic cleaner for 2 minutes. As a result of the ultrasonic cleaningstep, the ink is stripped from the polyester, along with the ITO formedon top of the ink.

[0033] In one embodiment in which conductive structures are formed onboth the top and bottom surfaces of the substrate, the processesillustrated in FIGS. 1-4 may comprise printing on both sides of a rollof Melinex 561 polyester (10″ wide, 4 mil thick, DuPont Teijin Films,Wilmington, Del.) using Film III Warm Red Ink (Environmental Inks andCoatings, Morganton, N.C.) on a Mark Andy 4200 flexographic press. Inone embodiment, the first side is printed with a first pattern A at oneprinting station, the web is run through a turn bar that flips the web,and the other side of the substrate is aligned and printed with a secondpattern B at the next plate station during the same printing run. In oneembodiment, the first pattern A comprises a negative image defining inkfree areas in which segment electrodes are to be formed, and the secondpattern B comprises a negative image defining ink free areas in whichconductive lines are to be formed. The patterns are aligned such thateach ink free segment electrode area in pattern A is aligned with theend of one ink free conductive line in pattern B, such as may bedesirable to allow for an electrical connection to be made between asegment electrode of side A and a conductive line of side B through aconductive via structure through the substrate. In one embodiment, about40′ of the polyester printed on both sides is sputtered on both sideswith 2500 angstroms of aluminum. A 5″×5″ piece of the aluminum coatedpolyester is developed by immersing it in a crystallizing dishcontaining methyl ethyl ketone, and putting the dish into a Fisher#FS220H ultrasonicator (Fisher Scientific, Pittsburg, Pa.) filled aninch deep with water for 2 minutes. This yields a polyester electrodewith one side having aluminum only in the segment pattern of the inkfree areas of A, and the opposite side having the electrode pattern ofthe ink free lines in B.

[0034] The ability to strip away the masking coating/ink lines afterdeposition of the thin film using a simple stripping process that is notdestructive of the thin film formed in the areas where the coating/inkpattern is not present (such as but not limited to the solvent andphysical peeling processes described above) facilitates a continuousfabrication process, such as a roll to roll fabrication process, becauseno time consuming batch processes such as image-wise exposure anddevelopment of photoresist, etching away portions of a thin film layernot covered by photoresist, or using solvents requiring special handlingor conditions to remove a photoresist layer after etching, are required.By saving time and using less expensive materials, the process describedherein is much less costly than other processes typically used to formon a polymer substrate the types of structures described herein.

[0035] FIGS. 5A-1 through 5D-2 illustrate an alternative process used inone embodiment to form a patterned thin film conductor on a substrate.The alternative process shown in FIGS. 5A-1 through 5D-2 employs a“positive” printed image in the sense that the coating/ink is printed inthe pattern of the thin film structure(s) to be formed, instead of beingused as described above in connection with FIGS. 1-4 to define areaswhere the thin film structure(s) is/are not to be formed. The processillustrated in FIGS. 5A-1 through 5D-2 is similar to that shown in FIGS.1-4 in that the process shown in FIGS. 5A-1 through 5D-2 employsprinting techniques to define the thin film structure(s) to be formed.The process shown in FIGS. 5A-1 through 5D-2 differs from the processshown in FIGS. 1-4, however, in that the printed pattern is not strippedoff the substrate, as described more fully below.

[0036] As shown in FIGS. 5A-1 and 5A-2, the thin film structures areformed on a substrate 502. The substrate 502 may be any of the substratematerials described above for use in the process illustrated by FIGS.1-4. In one embodiment, the substrate comprises 5 mil thick, 4507Polyester (available from Transilwrap, Franklin Park, Ill.). FIGS. 5B-1and 5B-2 show pattern lines 504 and 506 printed on the substrate 502. Inone embodiment, the pattern lines 504 and 506 are printed on thesubstrate 502 using GP20011 UV Process Magenta ink (Ink Systems Inc.,Commerce, Calif.) on an offset press. Any ink or other printablematerial may be used that has the characteristic that the subsequentlydeposited thin film adheres to the printed material more strongly thanit adheres to the substrate, as explained more fully below.

[0037] FIGS. 5C-1 and 5C-2 show a thin film layer 508 being formed onthe patterned surface of the substrate, covering both the printedpattern (lines 504 and 506) and the areas of the substrate 502 notcovered by the printed pattern. In one embodiment, the thin film 508 isformed by loading the patterned substrate into a vacuum system foraluminum evaporation at a film thickness of 120 nm.

[0038] FIGS. 5D-1 and 5D-2 show the remaining structures after theportions of the thin film 508 formed on the substrate 502 have beenremoved by a stripping process. Thin film structures 510 and 512 remainformed on printed lines 504 and 506, respectively. In one embodiment, asolvent is used to remove the portions of the thin film formed directlyon the substrate, but not the portions of the thin film formed over theprinted material, leaving thin film structures in the same pattern asthe printed material. In one embodiment, not shown in FIGS. 5D-1 and5D-2, some or all of the thin film formed on the side surfaces of theprinted material remains adhered to the side surfaces of the printedmaterial after the stripping process. In one embodiment, not all of thethin film formed directly on the substrate is removed by the strippingprocess, but the thin film formed directly on the substrate is removedsufficiently to cause there to be no measurable conductivity in theareas of the substrate where the printed material was not printed.

[0039] The alternative process shown in FIGS. 5A-1 through 5D-2 requiresthat the adhesion of the thin film layer to the substrate be low, theadhesion of the thin film layer to the printed material be high, theadhesion of the printed material to the substrate be high, and that thesolvent be such that it removes the portions of the thin film layer thatare formed directly on the substrate but not those portions of the thinfilm layer formed on the printed material.

[0040] In another alternative process, a substrate having a pooraffinity toward the thin film may be used. In one such embodiment, asurface treatment or primer coating such as a UV curable polymer layer,having good adhesion to both the substrate and the thin film is used toreplace the masking coating/ink in steps 104 and 106 of the processshown in FIG. 1. In this case, the thin film on the uncoated areas willbe removed in the stripping process to reveal the electrode pattern ortrace on the top of the surface treatment or primer coating. Thisalternative process is similar to that shown in FIGS. 5A-1 through 5D-2,with the primer coating comprising the printed material, such as patternlines 504 and 506.

[0041] FIGS. 6A-1 through 6F-2 illustrate a further alternative to theprocess shown in FIGS. 1-4. FIGS. 6A-1 and 6A-2 show a substrate 602. InFIGS. 6B-1 and 6B-2, pattern lines 604 and 606 have been printed ontothe substrate 602 using a printable first material. In one embodiment,as shown in FIGS. 6C-1 and 6C-2, the printed substrate is thenover-coated with a second material that is not soluble in at least onesolvent in which the first printable material is soluble, such that saidat least one solvent could be used to strip the first printable materialwithout also stripping the second material. In one embodiment, theprintable first material is hydrophobic (ie., water repelling) andsolvent soluble and has a low surface tension. In one embodiment, thesecond material is water-based and is repelled by the first material,such that the overcoat adheres only to those portions of the substratenot covered by the first material, forming areas 608, 610, and 612comprising the second (water-based) material. In one alternativeembodiment, the second material is not repelled by the first materialand the second material may partially or fully overcoat the patternlines 604 and 606 shown in FIGS. 6C-1 and 6C-2. In one such embodiment,in the regions in which the second material overcoats the firstmaterial, the second material may be less thick than in regions in whichthe second material is applied directly to the substrate (i.e., regionson the substrate in which the first material is not printed). In oneembodiment, the first material is stripped using a suitable solvent thatdoes not also strip away the second material, leaving the structureshown in FIGS. 6D-1 and 6D-2, in which the structures 604 and 606comprising the first material have been stripped away, leaving thestructures 608, 610, and 612 comprising the second material on thesubstrate 602. In one embodiment in which the second material maypartially or fully overcoat the printed first material, portions of thesecond material so formed on the first material are stripped away alongwith the portions of the first material on which they are formed,leaving the portions of the second material applied directly to thesubstrate (i.e., in regions where the first material was not present),as shown in FIGS. 6D-1 and 6D-2. In one embodiment, the solvent used tostrip away the first printable material (and, if applicable, portions ofthe second material formed thereon) comprises an aqueous solution orwater. In one embodiment, the solvent used to strip away the firstprintable material comprises a non-aqueous solvent or solution. Next, asshown in FIGS. 6E-1 and 6E-2, a thin film 614 is formed both on thestructures 608, 610, and 612 and on the portions of the substrate 602not covered by the second material, using one of the thin film materialsdescribed above. In one embodiment, the thin film is formed bysputtering, vapor deposition, spraying, or some other suitabletechnique. Finally, FIGS. 6F-1 and 6F-2 show the thin film structures616 and 618 that remain after the second material has been stripped awaywith an appropriate solvent, or another appropriate chemical ormechanical stripping process. In one embodiment, the solvent used tostrip away the first material is an aqueous basic solution and thesolvent used to strip away the second material is an aqueous acidicsolution, an aqueous neutral solution, or water. In one embodiment, thesolvent used to strip away the first material is an aqueous acidicsolution and the solvent used to strip away the second material is anaqueous basic solution, an aqueous neutral solution, or water. In oneembodiment, the solvent used to strip away the first material is anaqueous neutral solution or water and the solvent used to strip away thesecond material is an aqueous acidic solution or an aqueous basicsolution.

[0042] Under the process shown in FIGS. 6A-1 through 6F-2, the printedpattern of the first material comprises a positive image of the thinfilm structures to be formed. Once the first material has been strippedaway, as described above, the remaining second material comprises anegative image of the thin film structures to be formed. In a sense, thefirst material may be considered a mask that may be used to define areashaving very small dimensions, such as very fine lines, in which the thinfilm structures will not be present. While it may be difficult withpractically useful printing techniques, such as flexographic, to printsuch narrow lines in the first instance, for example because of physicallimitations, spreading of the ink after printing, etc., such techniquesmay be used readily to print less fine lines or less small areas withonly small gaps separating the lines or areas. A second material such asdescribed above may then be used to fill in the narrow spaces betweenthe areas covered by the first material, which first material may thenbe stripped away using an appropriate solvent, leaving behind very finelines or other shapes comprising the second material, which very finelines or shapes it may not have been practical to print in the firstinstance. These lines may then be used, as described above, as anegative image for the formation of adjacent thin film structuresseparated by very narrow gaps, for example.

[0043] In one embodiment, a physical stripping process such as peelingis used to reveal the thin film structures. For example, an adhesivetape having an appropriate cohesion strength and adhesion strength toITO is laminated onto an ITO/PET film pre-printed with a maskingcoating/ink. A subsequent peeling will remove the ITO either on the areaprinted with masking ink or on the area without the ink depending on thecohesion strength of the ink and the adhesion strengths at the ink-PETand ITO-PET interfaces. This stripping technique may be used with any ofthe processes described above.

[0044] In one embodiment, the process of FIGS. 6A-1 through 6F-2comprises printing a positive image of desired thin film thin filmstructures on a roll of Melinex 582 polyester (4 mil thick, 14″ wide,Dupont Teijin Films, Wilmington, Del.) using Film III Warm Red Ink(Environmental Inks and Coatings, Morganton, N.C.) on a Mark Andy 4200flexographic press. The printed portion of the polyester roll is thencoated with a solution consisting of 16 parts of aqueous 10% polyvinylpyrrolidinone (PVP-90, ISP Technologies, Inc., Wayne, N.J.), 0.40 partsSunsperse Violet (Sun Chemical, Cincinnati, Ohio), and 16 parts waterusing a #6 Meyer bar, and dried 1.5 minutes in an oven at 80° C. Thefilm is then placed in a crystallizing dish containing ethyl acetate. A10″×10″×12.5″ ultrasonication bath (BLACKSTONE-NEY, PROT-0512H EPultrasonic bath driven by a 12T MultiSonik™ generator) is filled withabout 4″ of water and the dish containing the film is floated in thewater and ultrasonicated at 104 KHz for 5 minutes. The film is thenremoved from the dish and dried 1.5 minutes in an oven at 80° C. At thecompletion of the drying step, the film has lines of PVP coating thatdefine a negative image of the originally printed positive image. Thepatterned polyester is next sputter coated with ITO using a CHA Mark 50roll coater to deposit a 1250 angstroms thick ITO film. The ITO coatedpatterned polyester is then ultrasonicated for 3 minutes in a beakercontaining water placed in a Fisher #FS220H ultrasonicator (FisherScientific, Pittsburg, Pa.). The film is then rinsed with de-ionizedwater and dried by blowing the water off with a stream of air. Theresulting film has ITO structures in the shape of the originally printedpositive image.

[0045] In one embodiment, the process shown in FIGS. 6A-1 through 6F-2comprises sputter deposition of ITO film on a PET substrate having ahydrophilic coating, e.g., Melnix 582, and printed using warm red ink(Environmental Ink). In one embodiment, this combination of materialsallows the ITO to be stripped from undesired areas ultrasonically usinga water based stripper.

[0046] In one embodiment, the water based stripper for ITO strippingcould be a surfactant solution such as JEM-126 (sodium tripolyphosphate,sodium silicate, nonyl phenol ethoxylate, ethylene glycol monbutyl etherand sodium hydroxide), detergent formulation 409, hydroproxide, anddeveloper Shipley 453, etc.

[0047] In one embodiment, the ITO stripping rate depends on the solventconcentration, solvent temperature, and the position of the substratefilm relative to the ultrasound transducer.

[0048] In one embodiment, prior to the ITO sputter deposition, the inkprinted PET surface is pre-treated with an appropriate plasma. In oneembodiment, such plasma pretreatment minimizes the generation ofmicro-cracks on the patterned ITO structures during the ITO strippingprocess. In addition, such plasma pre-treatment may in one embodimentprevent ITO residue from being generated on the printed ink area as aresult of removal of part of the printed ink pattern due to high-energyplasma, which may generate ITO residue on the printed ink area duringthe stripping process.

[0049] In order to eliminate the optical impact of minor ink residueappearing on the stripped ITO surface, in one embodiment a colorless inkprinted on the PET surface is preferred.

[0050] The additional examples listed below (identified as Embodiments Athrough F to facilitate comparison) further illustrate the benefits, interms of the patterning of thin film and the related manufacturing andhandling processes, e.g., of including in the masking coating/ink are-dispersible particulate as described herein, such as in the processesdescribed above in connection with FIGS. 1 through 4B.

[0051] In an Embodiment A, the following masking layer composition wasused for aluminum (Al) metal thin film patterning: 5.5 grams Celvol 203S(PVA from Celanese, Dallas, Tex., LMW, 87% hydrolysis), 5.5 grams PVPK-30 (from ISP Corp., Wayne, N.J.), and 0.1 grams of Xanthan Gum (fromAllchem, Inc., Dalton, Ga.) were dissolved slowly at room temperatureinto 39.2 grams of de-ionized water. To the masking composition, 0.23grams of Silwet L-7608 (from OSi Specialties, Middlebury, Conn.), wasadded. The resultant solution was used as the masking coating/ink forprinting a pattern on a substrate for metallization, e.g., as describedherein.

[0052] In an Embodiment B, the following masking layer composition wasused for aluminum (Al) metal thin film patterning: 3.0 grams of 20%dispersed silica (Sylojet 703C, from Grace Davison, Columbia, Md.) wasdiluted with 36.2 grams of de-ionized water. To this solution, 5.2 gramsCelvol 203S, 5.2 grams PVP K-30 and 0.1 grams of Xanthan Gum were addedslowly at room temperature then mixed at high shear rate. Finally, 0.23grams of Silwet L-7608 was added. The resultant solution was used as themasking coating/ink for printing a pattern on a substrate formetallization, e.g., as described herein.

[0053] In Embodiments C-F, the same procedure and binders of EmbodimentB were used, except that the weight percent of Silica in the dried filmswere changed to 10% in Embodiment C, 30% in Embodiment D, 60% inEmbodiment E, and 80% in Embodiment F.

[0054] For purposes of comparison, all of the masking solutions in theabove-described Embodiments A-F were screen printed on to a 2 milMelinex 453 PET film (ICI, UK) through a 330 mesh stencil to form anegative masking pattern. The roll-up properties of the printed filmwere evaluated by the blocking resistance at ambient and 50° C./80% RHconditions. The printed PET film was uniformly coated with an Al layerof 50 to 60 nm thickness by vapor deposition. Positive Al pattern wasdeveloped in water by selectively stripping off the Al layer on themasking layer to generate positive Al pattern on the area that was notprinted with the masking layer. The stripability or strippingselectivity is determined by the sharpness and shininess of theresultant Al image. The results are listed in Table 1 below (with theembodiment to which the data in each row applies indicated by the letterin the first column): TABLE 1 Film Silica Film Blocking Binder (wtBlocking after aging PVA/PVP % in Screen at in Stripability K-30 driedPrinting ambient 50° C./80% of Al by (1:1) film) quality condition RHWater A 97  0% Good Blocking Blocking Good severely B 92  5% GoodExcellent Good Good C 87 10% Good Excellent Excellent Excellent D 67 30%Good Excellent Excellent Excellent E 37 60% Good Excellent ExcellentExcellent F 17 80% Fair Excellent Excellent Fair-Good

[0055] It can be seen from Table 1 that the addition of the particulatesilica from 5 wt % to 80 wt % based on the dried masking film improvessignificantly both blocking resistance of the masking layer and thestripability of the Al layer on the masking layer. The presence of theparticulate dispersion in the masking layer also resulted in highlyshiny Al lines with fine line width and excellent integrity.

[0056] Although the foregoing invention has been described in somedetail for purposes of clarity of understanding, it will be apparentthat certain changes and modifications may be practiced within the scopeof the appended claims. It should be noted that there are manyalternative ways of implementing both the process and apparatus of thepresent invention. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

What is claimed is:
 1. A process for forming a patterned thin filmstructure on a substrate, comprising: printing a pattern on thesubstrate using a strippable material comprising 5-80% by weight of are-dispersible particulate, the printed strippable material defining anarea on the substrate where the thin film structure is to be formed bycomprising a negative image thereof such that the printed strippablematerial is present in areas on the substrate where the thin filmstructure is not to be formed and the printed strippable material issubstantially not present in the area on the substrate where the thinfilm structure is to be formed; depositing a thin film of material onthe patterned substrate; and stripping the strippable material from thesubstrate; whereby the strippable material and any thin film materialformed thereon are removed by said stripping leaving behind the thinfilm structure.
 2. The process for forming a patterned thin filmstructure on a substrate as recited in claim 1, wherein the strippablematerial comprises 10-60% by weight of the redispersible particulate. 3.The process for forming a patterned thin film structure on a substrateas recited in claim 1, wherein the strippable material comprises a watersoluble or water dispersible polymer as a binder.
 4. The process forforming a patterned thin film structure on a substrate as recited inclaim 3, wherein said water soluble polymer is selected from the groupconsisting of polyvinyl alcohol, polyvinylpyrrolidone,polyvinylpyridine, polyacrylic acid, polymethacrylic acid,polyacrylamide, polyethyleneglycol, poly(ethylene-co-maleic anhydride),poly (vinylether-co-maleic anhydride), poly(styrene-co-maleicanhydride), poly(butyelene-co-itaconic acid), PEOX, polystyrenesulfonate, cellulose derivatives such as hydroxyethyl cellulose,hydroxypropyl cellulose, methyl cellulose, carboxymethyl cellulose,xanthan gum, gum Arabic, gelatin, lecitin, and their copolymers.
 5. Theprocess for forming a patterned thin film structure on a substrate asrecited in claim 3, wherein the binder comprises a water dispersiblepolymer selected from water dispersible wax, alkaline dispersible wax,polyolefin, or acrylic latexes or dispersions.
 6. The process forforming a patterned thin film structure on a substrate as recited inclaim 1, wherein the strippable material comprises a solvent soluble orsolvent dispersible polymer as a binder.
 7. The process for forming apatterned thin film structure on a substrate as recited in claim 1,wherein the particulate is derived from silica, CaCO₃, CaSO₄, BaSO₄,Al₂O₃, TiO₂, hollow-spheres, non-film-forming latexes or dispersions,inorganic pigment, or organic pigment.
 8. The process for forming apatterned thin film structure on a substrate as recited in claim 1,wherein the particulate is a polymeric particle or a polymeric compositeparticle.
 9. The process for forming a patterned thin film structure ona substrate as recited in claim 1, wherein the strippable materialcomprises an additive selected from the group consisting of surfactants,dyes, curing agents, and plasticizers; whereby the presence of saidadditive facilitates the stripping of the strippable material subsequentto the deposition of the thin film.
 10. The process for forming apatterned thin film structure on a substrate as recited in claim 1,wherein the step of stripping comprises using a solvent to remove thestrippable material.
 11. The process for forming a patterned thin filmstructure on a substrate as recited in claim 10, wherein the solvent isselected from the group consisting of water, aqueous solutions,alcohols, ketones, esters, ethers, amides, hydrocarbons, alkylbenzenes,pyrrolidones, sulfones, DMSO, and their mixtures and derivatives. 12.The process for forming a patterned thin film structure on a substrateas recited in claim 1, wherein the thin film material is non-conductive.13. The process for forming a patterned thin film structure on asubstrate as recited in claim 1, wherein the thin film material issemi-conductive.
 14. The process for forming a patterned thin filmstructure on a substrate as recited in claim 1, wherein the thin filmmaterial is conductive.
 15. The process for forming a patterned thinfilm structure on a substrate as recited in claim 14, wherein theconductive thin film material is a material selected from the groupconsisting of metals, metal oxides, and their alloys and multilayercomposites.
 16. The process for forming a patterned thin film structureon a substrate as recited in claim 14, wherein the conductive materialis a metal selected from the group consisting of aluminum, copper, zinc,tin, molybdenum, nickel, chromium, silver, gold, iron, indium, thallium,titanium, tantalum, tungsten, rhodium, palladium, platinum and cobalt.17. The process for forming a patterned thin film structure on asubstrate as recited in claim 14, wherein the conductive material is ametal oxide selected from the group consisting of indium tin oxide(ITO), indium zinc oxide (IZO), aluminum zinc oxide, gadolinium indiumoxide, tin oxide, or fluorine-doped indium oxide.
 18. The process forforming a patterned thin film structure on a substrate as recited inclaim 1, wherein the step of depositing a thin film comprisessputtering.
 19. The process for forming a patterned thin film structureon a substrate as recited in claim 1, wherein the step of depositing athin film comprises vapor deposition.
 20. The process for forming apatterned thin film structure on a substrate as recited in claim 1,wherein the step of depositing a thin film comprises vacuum deposition.21. The process for forming a patterned thin film structure on asubstrate as recited in claim 1, wherein the step of depositing a thinfilm comprises electroplating.
 22. The process for forming a patternedthin film structure on a substrate as recited in claim 1, wherein thestep of depositing a thin film comprises electro-less plating.
 23. Theprocess for forming a patterned thin film structure on a substrate asrecited in claim 1, wherein the step of depositing a thin film compriseselectroforming.
 24. The process for forming a patterned thin filmstructure on a substrate as recited in claim 1, wherein the step ofprinting comprises flexographic printing.
 25. The process for forming apatterned thin film structure on a substrate as recited in claim 1,wherein the step of printing comprises driographic printing.
 26. Theprocess for forming a patterned thin film structure on a substrate asrecited in claim 1, wherein the step of printing compriseselectrophotographic printing.
 27. The process for forming a patternedthin film structure on a substrate as recited in claim 1, wherein thestep of printing comprises lithographic printing.
 28. The process forforming a patterned thin film structure on a substrate as recited inclaim 1, wherein the step of printing comprises gravure printing. 29.The process for forming a patterned thin film structure on a substrateas recited in claim 1, wherein the step of printing comprises thermalprinting.
 30. The process for forming a patterned thin film structure ona substrate as recited in claim 1, wherein the step of printingcomprises inkjet printing.
 31. The process for forming a patterned thinfilm structure on a substrate as recited in claim 1, wherein the step ofprinting comprises screen printing.
 32. The process for forming apatterned thin film structure on a substrate as recited in claim 1,wherein the substrate comprises a plastic substrate.
 33. The process forforming a patterned thin film structure on a substrate as recited inclaim 32, wherein the patterned thin film structure comprises a flexibleprinted circuit board or a portion of a flexible printed circuit board.34. The process for forming a patterned thin film structure on asubstrate as recited in claim 32, wherein the plastic substratecomprises a portion of a roll of plastic substrate.
 35. The process forforming a patterned thin film structure on a substrate as recited inclaim 34, wherein the process for forming a patterned thin filmstructure on a substrate is a component part of a roll-to-roll processfor fabricating a display.
 36. The process for forming a patterned thinfilm structure on a substrate as recited in claim 35, wherein thedisplay is an electrophoretic display.
 37. The process for forming apatterned thin film structure on a substrate as recited in claim 35,wherein the display is a passive matrix electrophoretic display.
 38. Theprocess for forming a patterned thin film structure on a substrate asrecited in claim 35, wherein the display is an in-plane switchingelectrophoretic display.
 39. The process for forming a patterned thinfilm structure on a substrate as recited in claim 35, wherein thedisplay is a dual-mode switching electrophoretic display comprising aplurality of electrophoretic cells filled with charged particles and acolored solvent in which the display is configured such that theparticles can be driven between the top and bottom of theelectrophoretic cells in a first mode and can be driven horizontally(in-plane) in a second mode.
 40. The process for forming a patternedthin film structure on a substrate as recited in claim 1, furthercomprising laminating the substrate with the thin film structure formedthereon to a display medium layer.
 41. The process for forming apatterned thin film structure on a substrate as recited in claim 40,wherein the display medium layer comprises a layer of electrophoreticcells.
 42. The process for forming a patterned thin film structure on asubstrate as recited in claim 41, wherein said electrophoretic cells areprepared by embossing.
 43. The process for forming a patterned thin filmstructure on a substrate as recited in claim 41, wherein saidelectrophoretic cells are closed and sealed by a polymeric sealinglayer.
 44. The process for forming a patterned thin film structure on asubstrate as recited in claim 1, wherein the thin film structurecomprises an electrode.
 45. The process for forming a patterned thinfilm structure on a substrate as recited in claim 44, wherein theelectrode is a segment electrode.
 46. The process for forming apatterned thin film structure on a substrate as recited in claim 44,wherein the electrode is a column electrode.
 47. The process for forminga patterned thin film structure on a substrate as recited in claim 44,wherein the electrode is a row electrode.
 48. The process for forming apatterned thin film structure on a substrate as recited in claim 44,wherein the electrode is a pixel electrode.
 49. The process for forminga patterned thin film structure on a substrate as recited in claim 1,wherein the thin film structure comprises a conductive trace.
 50. Aprocess for forming a patterned thin film structure on a substrate,comprising: printing on the substrate with a printable first material apattern that defines the area where the thin film structure is to beformed by comprising a positive image thereof such that the printablefirst material is printed in the area where the thin film structure isto be formed, the printable first material being strippable using afirst solvent; overcoating the printed surface of the substrate with asecond material that is not strippable using the first solvent;stripping the first material away using the first solvent in a processthat strips away the first material and any portions of the secondmaterial formed on the first material without stripping away theportions of the second material formed directly on the substrate, suchthat the second material remains coated on the portions of the substratewhere the first material was not present, thereby defining theboundaries of the thin film structure by comprising a negative imagethereof such that the second material is not present in and the firstmaterial has been stripped from the area where the thin film structureis to be formed; depositing a thin film layer on the patterned topsurface of the substrate; and stripping the second material to form thethin film structure.
 51. The process for forming a patterned thin filmstructure on a substrate as recited in claim 50, wherein the firstmaterial repels the second material such that the second material fillsin the areas of the substrate between the areas where the first materialhas been printed without coating the areas where the first material ispresent.
 52. The process for forming a patterned thin film structure ona substrate as recited in claim 50, wherein the first solvent is anaqueous solution or water.
 53. The process for forming a patterned thinfilm structure on a substrate as recited in claim 50, wherein the firstsolvent is a non-aqueous solvent or solution.
 54. The process forforming a patterned thin film structure on a substrate as recited inclaim 50, wherein the first solvent is an aqueous basic solution, andthe step of stripping the second material comprises using a secondsolvent comprising an aqueous acidic solution, an aqueous neutralsolution, or water.
 55. The process for forming a patterned thin filmstructure on a substrate as recited in claim 50, wherein the firstsolvent is an aqueous acidic solution and the step of stripping thesecond material comprises using a second solvent comprising an aqueousbasic solution, an aqueous neutral solution, or water.
 56. The processfor forming a patterned thin film structure on a substrate as recited inclaim 50, wherein the first solvent is an aqueous neutral solution orwater and the step of stripping the second material comprises using asecond solvent comprising an aqueous acidic solution or an aqueous basicsolution.
 57. A process for forming a patterned thin film structure on asubstrate, comprising: printing a first pattern on a first surface ofthe substrate using a strippable material comprising 5-80% by weight ofa re-dispersible particulate, the first pattern of strippable materialdefining an area on the first surface of the substrate where a firstthin film structure is to be formed; depositing a thin film of thin filmmaterial on the patterned first surface of the substrate; stripping thefirst pattern of strippable material from the substrate; printing asecond pattern on a second surface of the substrate using a strippablematerial comprising 5-80% by weight of a re-dispersible particulate, thesecond pattern of strippable material defining an area on the secondsurface of the substrate where a second thin film structure is to beformed; depositing a thin film of thin film material on the patternedsecond surface of the substrate; and stripping the second pattern ofstrippable material from the substrate; whereby the first pattern ofstrippable material, the second pattern of strippable material, and anythin film material formed on either the first or the second pattern ofstrippable material are removed leaving behind the first thin filmstructure on the first surface of the substrate and the second thin filmstructure on the second surface of the substrate.
 58. A process forforming a patterned thin film structure on a substrate, comprising:printing a first pattern on a first surface of the substrate using astrippable material comprising 5-80% by weight of a re-dispersibleparticulate, the first pattern of strippable material defining an areaon the first surface of the substrate where a first thin film structureis to be formed; printing a second pattern on a second surface of thesubstrate using a strippable material comprising 5-80% by weight of are-dispersible particulate, the second pattern of strippable materialdefining an area on the second surface of the substrate where a secondthin film structure is to be formed; depositing a thin film of materialon the patterned first surface and on the patterned second surface ofthe substrate; and stripping the first pattern and second pattern ofstrippable material from the substrate; whereby the first pattern ofstrippable material, the second pattern of strippable material, and anythin film material formed on either the first or the second pattern ofstrippable material are removed leaving behind the first thin filmstructure on the first surface of the substrate and the second thin filmstructure on the second surface of the substrate.
 59. The process forforming a patterned thin film structure on a substrate as recited inclaim 58, wherein the strippable material comprises 10-60% by weight ofthe redispersible particulate.
 60. The process for forming a patternedthin film structure on a substrate as recited in claim 1, wherein thestep of stripping comprises using solvent to remove the strippablematerial.
 61. The process for forming a patterned thin film structure ona substrate as recited in claim 1, wherein the step of strippingcomprises using mechanical pressure to remove the strippable material.62. The process for forming a patterned thin film structure on asubstrate as recited in claim 61, wherein using mechanical pressurecomprises brushing.
 63. The process for forming a patterned thin filmstructure on a substrate as recited in claim 61, wherein usingmechanical pressure comprises using a spray nozzle.
 64. The process forforming a patterned thin film structure on a substrate as recited inclaim 1, wherein the step of stripping comprises: applying an adhesivelayer having a higher adhesive strength with respect to the thin filmand/or strippable material than the adhesive strength of the strippablematerial to the substrate; and removing the strippable material and anythin film formed thereon by peeling off the adhesive layer.
 65. Theprocess for forming a patterned thin film structure on a substrate asrecited in claim 1, wherein the step of stripping comprises: applying anadhesive layer to the substrate after the thin film deposition step; andremoving the thin film on the area with the first printed material bypeeling off the adhesive layer.
 66. The method of claim 65, wherein thecohesion strength of the thin film and the adhesion strength betweenthin film and the substrate are stronger than any of the three forces:the cohesion strength of the strippable material, the adhesion strengthbetween the thin film and the strippable material, and the adhesionstrength between the strippable material and the substrate.